Leading Independent Proxy Advisory Firm Glass Lewis Recommends SINOVAC Shareholders Vote to Keep the Current Board in Place Glass Lewis concludes, "[T]he current board has demonstrated credible progress in restoring gove

Leading Independent Proxy Advisory Firm Glass

Lewis Recommends SINOVAC Shareholders Vote to Keep the Current Board in Place

Glass Lewis concludes, "[T]he current

board has demonstrated credible progress in restoring governance stability and operational normalcy. [...] The Dissident Group's

proposals, by contrast, rest on an inconsistent platform, rely on individuals linked to the governance failures of the past, and raise

material questions about their ability to credibly resolve the challenges ahead."

SINOVAC's Current Board of Directors encourages

shareholders to follow Glass Lewis' Recommendation and VOTE the WHITE proxy card "AGAINST" the misguided

proposals to remove the SINOVAC Board and appoint the Reconstituted Imposter Former Board Slate

Special Meeting of SINOVAC shareholders to be

held on July 8, 2025

To learn more visit: VoteSinovac.com

BEIJING, July 2, 2025 - The Board of Directors of SINOVAC

Biotech Ltd. (NASDAQ: SVA) ("SINOVAC" or the "Company"), a leading provider of biopharmaceutical products in China,

today announced that leading independent proxy advisory firm Glass, Lewis & Co. ("Glass Lewis") has recommended

that SINOVAC shareholders vote to keep the current SINOVAC Board in place by voting the WHITE proxy card "AGAINST" the election

of the Reconstituted Imposter Former Board Slate at the upcoming Special Meeting of Shareholders (the "Special Meeting")

to be held on Wednesday, July 9, 2025 at 8:00 a.m. China Standard Time (Tuesday, July 8, 2025 at 8:00 p.m. Atlantic

The SINOVAC Board issued the following statement in response to Glass

Lewis' recommendation:

"We are pleased that Glass Lewis rightly recognizes

that keeping the current Board in place is in the best interests of all SINOVAC shareholders. We have made incredible progress over the

past four months to restore fairness and deliver value to all SINOVAC shareholders, including declaring a US$55.00 per common share special

cash dividend and laying the groundwork for additional distributions to rightful shareholders, while retaining ample working capital for

investment and innovation.

"We remain committed to ending years of governance

failures committed by the Imposter Former Board and ensuring valid shareholders receive their fair share of distributions, while setting

the Company on a path of renewed growth and corporate accountability. As part of these efforts, we are planning an annual meeting of shareholders

in the second quarter of 2026 to nominate a full slate of highly-qualified and independent directors to guide SINOVAC's next phase

In making its recommendation that shareholders RETAIN

the Current Board and OPPOSE the Reconstituted Imposter Former Board Slate, Glass Lewis highlights the track record of misleading

claims and exploitation carried out by the Imposter Former Board, Advantech/Prime Success ("Advantech/Prime"), Vivo Capital,

SAIF and other members of the Former Management Buyout Consortium. This includes the:

Highlights from the Glass Lewis Report include1

SUPERIORITY OF THE CURRENT BOARD

1 Permission to use quotations was neither sought nor obtained.

NASDAQ TRADING HALT AND AUDITOR RESIGNATION

PIPE FINANCING AND RELATED LITIGATION

The Dissenting Investor Group's goal is clear: to reinstate a

complacent and complicit board that will allow them to seize control of SINOVAC at the expense of common shareholders. SINOVAC's

Board urges shareholders to protect their investment and the future of the Company by voting the WHITE proxy card today "AGAINST"

Proposal 1 and 2 at the Special Meeting.

For more details on the misdeeds and shareholder harm caused by the

Imposter Former Board and Dissenting Investor Group, visit our website www.votesinovac.com.

Your Vote is Important

Your vote on or before July 8 will be about the future of SINOVAC,

your receipt of your make-whole dividend payments in the near-term, and the long-term value of your investment.

We urge you to keep SINOVAC's Board in place and vote on the

WHITE proxy card "AGAINST" Proposal 1 to remove the current Board and "AGAINST" Proposal

2 to appoint the Reconstituted Imposter Former Board Slate. Your vote is critical to ensuring that SINOVAC remains on the path to stability,

growth, and value creation for all shareholders.

DISCARD any items you received asking you to vote for the Reconstituted

Imposter Former Board Slate. If you have already voted for the Reconstituted Imposter Former Board Slate, you can subsequently revoke

it by using the WHITE proxy card or WHITE voting instruction form to vote. Only your latest-dated vote will count!

The Special Meeting of Shareholders will be held on Wednesday, July 9,

2025 at 8:00 a.m. China Standard Time (Tuesday, July 8, 2025 at 8:00 p.m. Atlantic Standard Time). Valid shareholders of

record as of the close of business on May 19, 2025 are entitled to vote at the meeting.

If you have questions about how your vote can be counted, please contact

our proxy solicitor, Georgeson LLC, toll free at (844) 568-1506 in the U.S and (646) 543-1968 outside the U.S. or via email at SinovacSpecialMeeting@georgeson.com.

Sinovac Biotech Ltd. (SINOVAC) is a China-based biopharmaceutical

company that focuses on the R&D, manufacturing, and commercialization of vaccines that protect against human infectious diseases.

SINOVAC's product portfolio includes vaccines against COVID-19, enterovirus

71 (EV71) infected Hand-Foot-Mouth disease (HFMD), hepatitis A, varicella, influenza, poliomyelitis, pneumococcal disease, etc.

The COVID-19 vaccine, CoronaVac , has been approved for use in

more than 60 countries and regions worldwide. The hepatitis A vaccine, Healive , passed WHO prequalification requirements in

2017. The EV71 vaccine, Inlive , is an innovative vaccine under "Category 1 Preventative Biological Products"

and commercialized in China in 2016. In 2022, SINOVAC's Sabin-strain inactivated polio vaccine (sIPV) and varicella

vaccine were prequalified by the WHO.

SINOVAC was the first company to be granted approval for its H1N1 influenza

vaccine Panflu.1 , which has supplied the Chinese government's vaccination campaign and stockpiling program. The Company is

also the only supplier of the H5N1 pandemic influenza vaccine, Panflu , to the Chinese government stockpiling program.

SINOVAC continually dedicates itself to new vaccine R&D, with more

combination vaccine products in its pipeline, and constantly explores global market opportunities. SINOVAC plans to conduct more

extensive and in-depth trade and cooperation with additional countries, and business and industry organizations.

Important Additional Information and Where to Find It

In connection with SINOVAC's Special Meeting, SINOVAC has filed

with the U.S. Securities and Exchange Commission ("SEC") and mailed to shareholders of record entitled to vote

at the Special Meeting a definitive proxy statement and other documents, including a WHITE proxy card. SHAREHOLDERS ARE ENCOURAGED

TO READ THE PROXY STATEMENT AND ALL OTHER RELEVANT DOCUMENTS WHEN FILED WITH THE SEC AND WHEN THEY BECOME AVAILABLE BECAUSE THOSE DOCUMENTS

WILL CONTAIN IMPORTANT INFORMATION. Investors and other interested parties will be able to obtain the documents free of charge at

the SEC's website, www.sec.gov, or from SINOVAC at its website: https://www.sinovac.com/en-us/Investors/sec_filings. You

may also obtain copies of SINOVAC's definitive proxy statement and other documents, free of charge, by contacting SINOVAC's

Investor Relations Department at ir@sinovac.com.

Safe Harbor Statement

This announcement contains forward-looking statements within the meaning

of Section 21E of the Securities Exchange Act of 1934, as amended, and as defined in the U.S. Private Securities Litigation Reform

Act of 1995. These forward-looking statements can be identified by terminology such as "may," "will," "expect,"

"anticipate," "aim," "estimate," "intend," "plan," "believe,"

"potential," "continue," "is/are likely to" or other similar expressions. Such statements are based

upon current expectations and current market and operating conditions and relate to events that involve known or unknown risks, uncertainties

and other factors, all of which are difficult to predict and many of which are beyond the Company's or Board's control, which

may cause actual results, performance or achievements to differ materially from those in the forward-looking statements. Further information

regarding these and other risks, uncertainties or factors is included in the Company's filings with the U.S. Securities and Exchange

Commission. The Company and Board do not undertake any obligation to update any forward-looking statement as a result of new information,

future events or otherwise, except as required under law.

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